Up to my neck: the revision process

I've spent the past few weeks going through the new book (formerly 100 Breakfasts now officially titled THE SECRET OF EVERYTHING).  Ed and agents came back with suggestions and I had some thing I knew I wanted to smooth and fix, too.  

I wish I could say I had a process I use, over and over again, to rewrite a book, but I don't.  Different books require different fixes–tweaking a character's arc in one book, smoothing a bumpy or unrealistic plot in another; adding or taking away elements, shiftin